Synthesis and Characterization of Water-Soluble Chiral Conducting Polymer Nanocomposites

Abstract

We report the template-guided synthesis of water-soluble chiral conducting polymer nanocomposites. This synthetic route is facile and can be carried out on a large scale easily. Synthesis of water-soluble polyaniline nanocomposites is achieved by careful control of experimental parameters such as acid concentration, ionic strength, monomer/template ratio, total reagent concentration, order of reagent addition, temperature, and timing. Here, we show that a chiral polyaniline nanocomposite can be synthesized by addition of a chiral inducing agent (chiral acid) prior to polymerization and that the enantioselectivity of polyaniline can be controlled by the addition of the (+) or (−) form of the chiral acid. Further, we show that varying the chiral acid and/or salt concentration has a dramatic impact on the degree of chirality in the final polymer nanocomposite. The polyaniline nanocomposites were characterized by UV−vis, infrared (IR), circular dichroism spectroscopy, and tunneling electron microscopy. IR spectra show that the polyaniline and the template are intimately mixed at the molecular level. The strong polyaniline/template interaction results in nanocomposite chirality that is robust through repeated doping and dedoping cycles.